Guide apparatus for the propeller stream of vessels



0et .30,192s. 1,689,779

J. B. HIORT'H GUIDE APPARATUS FOR THE PROPELLER STREAM OF VESSELS Filed Sept. 22, 1927 [vvs/vroR Patented 0a. so, 192

PATENT. OFFICE- 1 'JENSQ BRODERSEN HIORTH, or HovIK, NEAR osLoNonwAY.

euinnnrrnne'rns Fon'rnn rnornnnnn srnEni/r or vnssnns.

Application filed September 22, 1927, SeriaI'No. 221,246, and in Norway Se'ptember 28, 1926.

Prior to the-present invention it has been suggested in connection with vessels driven by one or more screw propellers to attach guide vanes for the propeller stream to the rudder post or, .where balanced rudders are used, in connection with the same, in order Heretofore, in most constructions of this kind, the guide Vane has been arranged symmetrically to the vertical plane through the center line of. the propeller shaft. It has, however, also been suggested where there was the question of application of guide apparatus for the propeller stream to existing vessels, to fix the guide vane at the side. of the rudder post and thus somewhat asymmetrically to the vertical plane through the center line or axis of the propeller shaft.

In these known constructions the ruddel always has been constructed symmetrically to the said plane, whereby, owing to the asymmetrical fitting of the guide vanes, the flowing of the water to both sides of the rudder was unequal, which gave a reduced elliciency of-the propeller and a reduced effect of the rudder. Furthermore'itwas always necessary to locate the forward ;or leading edge of the guide vane considerably out of the vertical plane through the center line of the propeller shaftjwhich, as experience shows, is unfavourable to the efli ciency of the guide apparatus.

According to this invention the aforesaid defects are avoided in thatthe center line of the horizontal section of the rudder is arranged asymmetrically to the axis of rota-- tion of the rudder which is situated in the vertical. plane through thecenter line of the propeller shaft, in order to obtain equal flow of the water to both sides of the rudder;

, with an asymmetry equal to or approximately equal to the asymmetry of the guide eana Furthermore according ta the present cavity, a-port.

invention the forward or leading edge of the guide vane islocated in or approximately in mined with a View to obtaining the most favourable passage of the stream lines at the deflection of the propeller stream. l

The center line of the rudder section may be straight or curvedand the surfaces of the rudder also may be straight or curved. If the rudder and the guide Vane are constructed with the same thickness soas to form together a body with continuous, smooth surfaces, then this body will, because of its asymmetry,-already in the midship position of the rudder have a vaneor shovel form cross section whereby, besides an improvement in the efficiency of'the propeller, a steering action is obtained with the rudder in midship position, and by turning of the rudder a considerably greater side pressure is obtained than at the same turning of the usual rudder, i. e', a shorter turning of the rudder is necessaryfor obtaining of the desired-rudder action. At the same time by suitable shaping the rudder section the center of pressure of the water can be broughtcomparatively near to the axis of turning of the rudder and displacement of the center of pressure duringturning of the rudder is reduced to a minimum.

Some embodiments of my invention are illustrated in the accompanying drawing in which all figures show horizontal sections through guide vane and rudder.

Fig. 1 shows an arrangement with the guide vane 1 attached asymn'ietrically to the rudder post 2, and with asymmetrically formed rudder 3, the cross section of which has a st-raight center line. .Fig. 2 shows a similar arrangement, only in that the'rudder 3 is formed as a vane or shovel with 0011- In both these embodiments the guide vane and rudderare constructed of platesand angles, suitable for mounting on an existing structure. For new constructions the rudder post and rudder frame, of course, may beforehand be given the form most suitable for the construction.

Fig. 3 shows an' asymmetrically formed balanced rudder 4, the forwardedge. of whichv forms a guide vane 5. 6 is the pivot axis of I the rudder. Fig. 4 also shows a balanced rudder 4, provided vith guide ease the? Bit rudder being given the form of a vane with stronger curve and concavity a-port, In

this figure also 6 is the pivot axis of the rudder. I Having now particularly described and ascertained the nature of my said invention and in What manner-the same is to beperformed, I declare that What I claim "is: v 1. In combination a shipsrudder, guide vane for the propeller stream attached to the rudder post asymmetrically to the vertical plane 'through the center line of the propeller shaft, the rudder being of the stream 1ine type and having the axis of its pivots arranged off the median line through the horizontal section of the rudder with an asymmetry approximately corresponding to the asymmetry of the guide vane. 2. In combination a balanced ships rudder of the stream line type, a guide vane for the propeller stream rigid tlierewlth, the

axis of the pivots of the rudder being arranged off the median line through the horizontal section or the rudder.

3. In comblnat on aships rudder, a guide vane arranged asymmetrically to the verti- 7 "'oa'l plane through the axis "or the propeller shaft, the axis of the pivots oi the rudder being arrangedofi' the'n'iedianline through the horizontal-section of the rudder with an asymmetry approximately corresponding to the asymmetry of the guide vane, and the forward edge of-the guide vane being situ- 

